6 Diamond Coated Sanding Drums Jewelers Lapidary Tools This is a new set of six 150 grit diamond coated sanding drums These are great for filing glass, ceramics, tile, brick, plastics, wood, fiberglass, stone, rock carbide, gold, platinum, silver, metals or anything else that is hard Longevity is assured as the diamond particles are electroplated onto the surface of the metal Recommended for jewelers, lapidary, hobby&amp;craft, modeling, home repair, etc Each drum measures approximately 1/2" (13 mm) in diameter